The field features an Olympic medalist, the reigning world indoor champion, sensational kickers, and a hometown hero.
Check out these exciting action shots from a busy week in Beijing!
Ethiopia's Genzebe Dibaba upset in women's 5,000m final.
She won her country's first ever marathon gold medal at the World Championships.
Marina Arzamasova of Belarus won the women's 800m final.
He was taken out just moments after winning the 200 meters.
The favorites dominated despite slow starts in both events.
She was the only American woman to move on in the event.
Emma Coburn of the U.S. takes fifth.
Reigning world and Olympic champion Mo Farah survives another scare.